In cases where functional fillers selected from among thermally conductive fillers, fluorescent fillers, electrically conductive fillers, dielectric fillers, insulating fillers, light-diffusing fillers, translucent fillers, coloring fillers and reinforcing fillers are blended with resin compositions, it is possible to obtain greases, gels, cured rubbers, coating agents and phase change materials having a variety of functions, and such functional fillers are therefore widely used on an industrial scale. In particular, as electronic parts, such as transistors, ICs and memory elements, mounted on printed circuit boards and hybrid ICs have advanced in terms of density and integration in recent years, a variety of thermally conductive silicone compositions have been used in order to efficiently dissipate heat from these electronic parts. Thermally conductive silicone greases, thermally conductive silicone gel compositions and thermally conductive silicone rubber compositions are known as such thermally conductive silicone compositions.
For example, thermally conductive silicone compositions which contain a silicone oil as a primary component and which also contain an inorganic filler such as zinc oxide or an alumina powder (see Japanese Unexamined Patent Application Publication Nos. S50-105573, S51-55870 and S61-157587), a thermally conductive silicone composition consisting of an organopolysiloxane, an organopolysiloxane having an alkoxy group or acyloxy group bonded to a silicon atom, a thermally conductive filler and a curing agent (see Japanese Unexamined Patent Application Publication No. 2000-256558) and a thermally conductive silicone composition containing an organopolysiloxane, a curing agent and a thermally conductive filler that has been surface treated with a silaklylene-oligosiloxane having an alkoxy group bonded to a silicon atom (see Japanese Unexamined Patent Application Publication No. 2001-139815) have been proposed as such thermally conductive silicone compositions.